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          对象池实战-编写一个数据库连接池
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      <time title="创建时间：2021-08-01 16:49:55 / 修改时间：20:33:00" itemprop="dateCreated datePublished" datetime="2021-08-01T16:49:55+08:00">2021-08-01</time>
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        <h1 id="前言"><a href="#前言" class="headerlink" title="前言"></a>前言</h1><p>通过对象池编写一个数据库连接池，深入学习，巩固对象池用法。</p>
<ul>
<li><p>能代替其它数据库连接池产品</p>
<ul>
<li>Hikari、DBCP、Tomcat、Druid…</li>
</ul>
</li>
<li><p>带监控，随时了解了解连接池的情况</p>
</li>
</ul>
<h1 id="ConnectionPooledObjectFactory"><a href="#ConnectionPooledObjectFactory" class="headerlink" title="ConnectionPooledObjectFactory"></a>ConnectionPooledObjectFactory</h1><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">ConnectionPooledObjectFactory</span></span></span><br><span class="line"><span class="class">  <span class="keyword">implements</span> <span class="title">PooledObjectFactory</span>&lt;<span class="title">MyConnection</span>&gt; </span>&#123;</span><br><span class="line">  <span class="keyword">private</span> ObjectPool&lt;MyConnection&gt; objectPool;</span><br><span class="line"></span><br><span class="line">  <span class="function"><span class="keyword">public</span> ObjectPool&lt;MyConnection&gt; <span class="title">getObjectPool</span><span class="params">()</span> </span>&#123;</span><br><span class="line">    <span class="keyword">return</span> objectPool;</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">setObjectPool</span><span class="params">(ObjectPool&lt;MyConnection&gt; objectPool)</span> </span>&#123;</span><br><span class="line">    <span class="keyword">this</span>.objectPool = objectPool;</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> PooledObject&lt;MyConnection&gt; <span class="title">makeObject</span><span class="params">()</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">    Class.forName(<span class="string">&quot;com.mysql.jdbc.Driver&quot;</span>);</span><br><span class="line">    Connection connection = DriverManager.getConnection(</span><br><span class="line">      <span class="string">&quot;jdbc:mysql://localhost:3306/xxxx?useUnicode=true&amp;characterEncoding=UTF-8&amp;autoReconnect=true&quot;</span>,</span><br><span class="line">      <span class="string">&quot;root&quot;</span>,</span><br><span class="line">      <span class="string">&quot;root123&quot;</span></span><br><span class="line">    );</span><br><span class="line">    MyConnection myConnection = <span class="keyword">new</span> MyConnection();</span><br><span class="line">    myConnection.setConnection(connection);</span><br><span class="line">    myConnection.setObjectPool(objectPool);</span><br><span class="line">    <span class="keyword">return</span> <span class="keyword">new</span> DefaultPooledObject&lt;&gt;(myConnection);</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">destroyObject</span><span class="params">(PooledObject&lt;MyConnection&gt; p)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">    p.getObject().close();</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">boolean</span> <span class="title">validateObject</span><span class="params">(PooledObject&lt;MyConnection&gt; p)</span> </span>&#123;</span><br><span class="line">    Connection connection = p.getObject();</span><br><span class="line">    <span class="keyword">try</span> &#123;</span><br><span class="line">      PreparedStatement statement = connection.prepareStatement(<span class="string">&quot;SELECT 1&quot;</span>);</span><br><span class="line">      ResultSet resultSet = statement.executeQuery();</span><br><span class="line">      <span class="keyword">int</span> i = resultSet.getInt(<span class="number">1</span>);</span><br><span class="line">      <span class="keyword">return</span> i == <span class="number">1</span>;</span><br><span class="line">    &#125; <span class="keyword">catch</span> (SQLException e) &#123;</span><br><span class="line">      <span class="keyword">return</span> <span class="keyword">false</span>;</span><br><span class="line">    &#125;</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">activateObject</span><span class="params">(PooledObject&lt;MyConnection&gt; p)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">    <span class="comment">// 可以把connection额外的配置放到这里</span></span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">passivateObject</span><span class="params">(PooledObject&lt;MyConnection&gt; p)</span> <span class="keyword">throws</span> Exception </span>&#123;</span><br><span class="line">    <span class="comment">// 钝化</span></span><br><span class="line">    MyConnection myConnection = p.getObject();</span><br><span class="line">    Statement statement = myConnection.getStatement();</span><br><span class="line">    <span class="keyword">if</span> (statement != <span class="keyword">null</span>) &#123;</span><br><span class="line">      statement.close();</span><br><span class="line">    &#125;</span><br><span class="line">  &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

<h1 id="MyDataSource"><a href="#MyDataSource" class="headerlink" title="MyDataSource"></a>MyDataSource</h1><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyDataSource</span> <span class="keyword">implements</span> <span class="title">DataSource</span> </span>&#123;</span><br><span class="line">  <span class="keyword">private</span> GenericObjectPool&lt;MyConnection&gt; pool;</span><br><span class="line"></span><br><span class="line">  <span class="function"><span class="keyword">public</span> GenericObjectPool&lt;MyConnection&gt; <span class="title">getPool</span><span class="params">()</span> </span>&#123;</span><br><span class="line">    <span class="keyword">return</span> pool;</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">setPool</span><span class="params">(GenericObjectPool&lt;MyConnection&gt; pool)</span> </span>&#123;</span><br><span class="line">    <span class="keyword">this</span>.pool = pool;</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="title">MyDataSource</span><span class="params">()</span> </span>&#123;</span><br><span class="line">    ConnectionPooledObjectFactory factory = <span class="keyword">new</span> ConnectionPooledObjectFactory();</span><br><span class="line">    <span class="keyword">this</span>.pool = <span class="keyword">new</span> GenericObjectPool&lt;&gt;(factory);</span><br><span class="line">    factory.setObjectPool(pool);</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> Connection <span class="title">getConnection</span><span class="params">()</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="keyword">try</span> &#123;</span><br><span class="line">      <span class="keyword">return</span> <span class="keyword">this</span>.pool.borrowObject();</span><br><span class="line">    &#125; <span class="keyword">catch</span> (Exception e) &#123;</span><br><span class="line">      <span class="keyword">throw</span> <span class="keyword">new</span> SQLException(<span class="string">&quot;获取连接失败！&quot;</span>, e);</span><br><span class="line">    &#125;</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> Connection <span class="title">getConnection</span><span class="params">(String username, String password)</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="keyword">return</span> <span class="keyword">this</span>.getConnection();</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="keyword">public</span> &lt;T&gt; <span class="function">T <span class="title">unwrap</span><span class="params">(Class&lt;T&gt; iface)</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="keyword">throw</span> <span class="keyword">new</span> UnsupportedOperationException(<span class="string">&quot;不支持的操作！&quot;</span>);</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">boolean</span> <span class="title">isWrapperFor</span><span class="params">(Class&lt;?&gt; iface)</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="keyword">throw</span> <span class="keyword">new</span> UnsupportedOperationException(<span class="string">&quot;不支持的操作！&quot;</span>);</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> PrintWriter <span class="title">getLogWriter</span><span class="params">()</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="keyword">throw</span> <span class="keyword">new</span> UnsupportedOperationException(<span class="string">&quot;不支持的操作！&quot;</span>);</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">setLogWriter</span><span class="params">(PrintWriter out)</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="keyword">throw</span> <span class="keyword">new</span> UnsupportedOperationException(<span class="string">&quot;不支持的操作！&quot;</span>);</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">setLoginTimeout</span><span class="params">(<span class="keyword">int</span> seconds)</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="keyword">throw</span> <span class="keyword">new</span> UnsupportedOperationException(<span class="string">&quot;不支持的操作！&quot;</span>);</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">int</span> <span class="title">getLoginTimeout</span><span class="params">()</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="keyword">throw</span> <span class="keyword">new</span> UnsupportedOperationException(<span class="string">&quot;不支持的操作！&quot;</span>);</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> Logger <span class="title">getParentLogger</span><span class="params">()</span> <span class="keyword">throws</span> SQLFeatureNotSupportedException </span>&#123;</span><br><span class="line">    <span class="keyword">throw</span> <span class="keyword">new</span> UnsupportedOperationException(<span class="string">&quot;不支持的操作！&quot;</span>);</span><br><span class="line">  &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

<h1 id="MyConnection"><a href="#MyConnection" class="headerlink" title="MyConnection"></a>MyConnection</h1><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 1. 回收statement</span></span><br><span class="line"><span class="comment">// 2. 回收resultSet</span></span><br><span class="line"><span class="comment">// 3. 复用Connection</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">MyConnection</span> <span class="keyword">implements</span> <span class="title">Connection</span> </span>&#123;</span><br><span class="line">  <span class="keyword">private</span> Connection connection;</span><br><span class="line">  <span class="keyword">private</span> Statement statement;</span><br><span class="line">  <span class="keyword">private</span> ObjectPool&lt;MyConnection&gt; objectPool;</span><br><span class="line">  </span><br><span class="line">  <span class="comment">// 篇幅有限，省略其它方法</span></span><br><span class="line">  </span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> Statement <span class="title">createStatement</span><span class="params">()</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="keyword">return</span> <span class="keyword">this</span>.connection.createStatement();</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> PreparedStatement <span class="title">prepareStatement</span><span class="params">(String sql)</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    PreparedStatement prepareStatement = <span class="keyword">this</span>.connection.prepareStatement(sql);</span><br><span class="line">    <span class="keyword">this</span>.statement = prepareStatement;</span><br><span class="line">    <span class="keyword">return</span> prepareStatement;</span><br><span class="line">  &#125;</span><br><span class="line">  </span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> PreparedStatement <span class="title">prepareStatement</span><span class="params">(String sql, String[] columnNames)</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    PreparedStatement statement = <span class="keyword">this</span>.connection.prepareStatement(sql, columnNames);</span><br><span class="line">    <span class="keyword">this</span>.statement = statement;</span><br><span class="line">    <span class="keyword">return</span> statement;</span><br><span class="line">  &#125;</span><br><span class="line">  </span><br><span class="line">  <span class="meta">@Override</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="keyword">void</span> <span class="title">close</span><span class="params">()</span> <span class="keyword">throws</span> SQLException </span>&#123;</span><br><span class="line">    <span class="comment">// 如果底层的Connection已经关闭</span></span><br><span class="line">    <span class="keyword">if</span> (<span class="keyword">this</span>.isClosed()) &#123;</span><br><span class="line">      <span class="keyword">try</span> &#123;</span><br><span class="line">        objectPool.invalidateObject(<span class="keyword">this</span>);</span><br><span class="line">      &#125; <span class="keyword">catch</span> (Exception e) &#123;</span><br><span class="line">        <span class="keyword">throw</span> <span class="keyword">new</span> SQLException(e);</span><br><span class="line">      &#125;</span><br><span class="line">    &#125;</span><br><span class="line">    <span class="comment">// 底层Connection没有关闭，可以继续复用</span></span><br><span class="line">    <span class="keyword">else</span> &#123;</span><br><span class="line">      <span class="keyword">try</span> &#123;</span><br><span class="line">        objectPool.returnObject(<span class="keyword">this</span>);</span><br><span class="line">      &#125; <span class="keyword">catch</span> (Exception e) &#123;</span><br><span class="line">        <span class="keyword">this</span>.connection.close();</span><br><span class="line">        <span class="keyword">throw</span> <span class="keyword">new</span> SQLException(e);</span><br><span class="line">      &#125;</span><br><span class="line">    &#125;</span><br><span class="line">  &#125;</span><br><span class="line">  </span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

<h1 id="如何使用？"><a href="#如何使用？" class="headerlink" title="如何使用？"></a>如何使用？</h1><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@Bean</span></span><br><span class="line"><span class="meta">@Primary</span></span><br><span class="line"><span class="function"><span class="keyword">public</span> DataSource <span class="title">dataSource</span><span class="params">()</span></span>&#123;</span><br><span class="line">    <span class="keyword">return</span> <span class="keyword">new</span> DMDataSource();</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>

<h1 id="如何使用-spring-boot-starter-actuator-添加监控？"><a href="#如何使用-spring-boot-starter-actuator-添加监控？" class="headerlink" title="如何使用 spring-boot-starter-actuator 添加监控？"></a>如何使用 <code>spring-boot-starter-actuator</code> 添加监控？</h1><figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">// 可以用/actuator/datasource</span></span><br><span class="line"><span class="meta">@Endpoint(id = &quot;datasource&quot;)</span></span><br><span class="line"><span class="keyword">public</span> <span class="class"><span class="keyword">class</span> <span class="title">DataSourceEnpoint</span> </span>&#123;</span><br><span class="line">  <span class="keyword">private</span> MyDataSource dataSource;</span><br><span class="line"></span><br><span class="line">  <span class="function"><span class="keyword">public</span> <span class="title">DataSourceEnpoint</span><span class="params">(MyDataSource dataSource)</span> </span>&#123;</span><br><span class="line">    <span class="keyword">this</span>.dataSource = dataSource;</span><br><span class="line">  &#125;</span><br><span class="line"></span><br><span class="line">  <span class="meta">@ReadOperation</span></span><br><span class="line">  <span class="function"><span class="keyword">public</span> Map&lt;String, Object&gt; <span class="title">pool</span><span class="params">()</span> </span>&#123;</span><br><span class="line">    GenericObjectPool&lt;MyConnection&gt; pool = dataSource.getPool();</span><br><span class="line">    HashMap&lt;String, Object&gt; map = Maps.newHashMap();</span><br><span class="line">    map.put(<span class="string">&quot;numActive&quot;</span>, pool.getNumActive());</span><br><span class="line">    map.put(<span class="string">&quot;numIdle&quot;</span>, pool.getNumIdle());</span><br><span class="line">    map.put(<span class="string">&quot;createdCount&quot;</span>, pool.getCreatedCount());</span><br><span class="line">    <span class="keyword">return</span> map;</span><br><span class="line">  &#125;</span><br><span class="line">&#125;</span><br></pre></td></tr></table></figure>


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